NE101 Lec 30: Sleep & Rhythms

Regular rhythms are also called __________.

oscillations

______ are measured in seconds per cycle.

periods

________ is measured in Hz (cycles per second).

frequency

_______ is the magnitude of a wave’s peaks and troughs.

amplitude

Brain rhythms tend to be __________ frequency and __________ oscillation.

high, low

EEG electrodes placed on the scalp measure changes in __________ across brain areas.

summated voltage

EEG signals reflect changes in ionic currents across groups of neurons, not __________.

action potentials

ECoG electrodes are placed under the skull beneath the __________.

dura mater

ECoG can both record and apply __________ to identify cortical function.

stimulation

ECoG is favored over EEG because signals are not __________ by the skull.

dampened

ECoG can identify more __________ locations of electrical activity than EEGs.

specific

LFPs are recorded from electrodes implanted directly into the __________.

brain

Chronic LFP electrodes can be used for deep brain stimulation in disorders like __________.

parkinson’s disease

LFPs can also record individual __________.

action potentials

EEG measures signals from the __________.

scalp

ECoG measures signals from the __________ surface.

brain

LFP measures changes in electrical fields __________ the brain.

inside

Single-unit recording measures the voltage of a single __________.

neuron

High-amplitude EEG waves reflect high __________ across neurons.

synchrony

Low amplitude does not mean low activity, but instead low __________.

synchrony

High-frequency rhythms in the brain generally have __________ amplitudes.

low

Phase refers to a specific part of a __________ cycle.

rhythmic

Phase locking means neurons fire more often at particular __________ of a rhythm.

phases

Phase locking may facilitate __________ between brain areas.

communication

The binding hypothesis says synchronized rhythms can help bind parts of a __________ or action together.

perception

Seizures involve pathological __________ of neuronal activity.

synchronization

Seizures often originate in the __________ and ________.

hippocampus, temporal lobe

Regions with recurrent connections, like __________, are particularly vulnerable.

CA3

Awake brain activity is __________ frequency.

high

Non-REM sleep shows __________ amplitude and __________ frequency EEG activity.

high, low

REM sleep EEG resembles the __________ state.

awake

REM sleep is also called __________ sleep.

paradoxical

During REM sleep, the body is completely __________.

paralyzed

Dreaming primarily occurs during __________ sleep.

REM

Non-REM sleep is “__________” sleep.

deeper

EEG shows large amplitude, slow __________.

fluctuations

The body can move during non-REM sleep, except during __________ episodes.

sleepwalking

Most of the night is spent in __________ sleep.

non-REM

REM bout duration gradually __________ across the night.

increases

Sleep is not passive—modulatory systems in the brainstem and __________ regulate sleep.

hypothalamus

Wakefulness-promoting structures are collectively called the __________ system.

reticular activating

Circadian rhythms are daily cycles in physical, mental, and __________ functions.

behavioral

The body’s “clock” is the __________ nucleus in the hypothalamus.

suprachiasmatic

The SCN receives light signals from specialized ganglion cells in the __________.

retina

The SCN is __________, meaning it can adjust to new light-dark cycles.

plastic

The restoration theory states sleep allows the brain and body to __________.

recover

The adaptation theory suggests sleep evolved for __________ advantages.

survival

Prolonged sleep deprivation impairs concentration, __________, and cognitive abilities.

memory

Learning and task performance improve after __________.

sleep

REM sleep duration increases after learning __________ tasks.

difficult

Interrupting REM sleep can __________ learning.

impair

During sleep, hippocampal __________ cells replay activity sequences.

place

Replay may aid __________ memory consolidation.

episodic

Blocking replay with electrical stimulation can __________ learning.

impair

Constant potentiation during wakefulness increases net brain __________.

excitability

Sleep allows circuits to rebalance by scaling synaptic strengths __________.

down

Homeostasis prevents excessive synaptic strengthening and __________.

hyperexcitability

Dreaming may allow the brain to explore novel __________ never experienced before.

possibilities

Place cells can encode unique, never-before-taken __________ during sleep.

trajectories